For manufacturing of semiconductor devices, long oven processes are employed at high temperatures to diffuse dopants, which are implanted into the semiconductor material, in the semiconductor lattice of the semiconductor material. The dopants create p- and n-doped regions needed for device operability. The mobility of charge carriers can be affected by intrinsic impurities and defects of the semiconductor material. For example, silicon-based semiconductor materials may contain oxygen. When the oxygen concentration is too high, oxygen precipitates. Furthermore, the semiconductor material may contain so-called COPs (Crystal Originated Particles) which additionally influence the mobility of charge carriers and can thus worsen the performance of the final semiconductor device.
So-called FZ-semiconductor material manufactured using a floating zone process has a low oxygen concentration. However, FZ-semiconductor material is expensive. The more cheap CZ-semiconductor material, manufactured using the so-called Czochralski process, has a comparably high oxygen concentration due to the dissolution of material of the crucible used for melting the semiconductor material. Due to cost reasons, CZ-semiconductor material is typically the material of choice.
Attempts have been made to reduce the influence of oxygen precipitates and COPs on the charge carrier mobility in CZ-based semiconductor materials. However, there is need for further improvement.